Interconnected – Dubai Junction Light Trails
The bribe requested by security to access this roof was fairly typical in Dubai, we were told – 100 dirhams per person. We were limited to 45 minutes, which meant we’d be very pushed for time when blue hour arrived. Nevertheless, despite the time restriction, we all came away with images we were happy with, which has been the story of our trip so far, fortunately.
Tonight, before we fly, we have a window of opportunity to shoot Meydan bridge – a bridge built for use only by the royal family. I tried to shoot this last week, but Jaguar were filming a commercial for a new car, so we were denied access. Fingers crossed we have better luck today.
The Cool Bits – Technical Info
Processing Time: Infinity times by 10
Exposure Blending method: Luminosity Masks
No. of Exposures: 32
EV Range: o + -2 (four base exposures & four under-exposed exposures)
Aperture: From f/6.3 (base exposures) and f/14 (light trails).
Focal Length: 14mm
Lens: Nikkor 14-24mm f/2.8
Camera: Nikon D800
Plugins: Nik Color Efex
Luminosity Masks: Used to recover selected highlights
Workflow Explanation – Interconnected – Dubai Junction Light Trails
This image took longer to finish than I’d expected. I had a very strong idea of what I wanted from the scene, but Photoshop had other ideas. On the first attempt, I went through the entire workflow only to realise at the last hurdle that there was a small stitching error. I started again from scratch, and finished it the second time.
I had planned to shoot 4 vertical tiles, rather than horizontal tiles, for this pano. I found horizontal tiles to be just as efficient, and more comfortable, as we were shooting over a large wall which obscured some of our view.
In terms of shooting, I composed the first tile, fired off 5 brackets of 1 stop difference, and then shot 6 or more longer exposures for the light trails. Then I swiveled the ballhead down slightly to do the same with the next tile. In the end, I used 32 exposures to get the final result.
In post, I added a cooler temperature to the files in ACR. Photoshop didn’t like the test-stitch I performed on the base files. There was, as can be expected at 14mm, a lot of distortion. To counter this, I treated each tile as its own image. In other words, I dragged the base exposure for the first tile in Photoshop. I then opened a darker exposure, which I used to control the highlights in the base exposure.
Then I dragged in the light trails exposures and blended them into the base exposure using the Blend Mode Lighten. To finish, I corrected all of the distortion so that all of the buildings, and the horizon, were straight.
I did exactly the same thing with the other 3 tiles. In the end I had 4 tiles, all with controlled highlights, all with decent light trails, and all had perspective and barrel correction.
This allowed Photoshop to simply place each exposure on top of one another, with only 1 minor incident.
If you look at the base exposures you will see that the light trails do not extend all the way down the image. This is impossible as we are above the cars from this point, and so lose sight of the car lights. So to create light trails, I copied the existing light trails and warped/distorted them until they fit the scene correctly.
Although I was editing in 16bit mode, I started to see a lot of banding in the sky. I tried every method under the sun to remove it. The only thing that reduced it well, was adding some noise to the sky. However, the noise was clearly noticeable. Instead, I examined the Channels palette (next to the layers panel), and saw that the Red and Green channels contained A LOT of banding, while the blue channel was perfect.
I added noise to the Red and Green channels, which reduced the banding but didn’t create excessive noise in the sky.
To finish, I painted a gentle vignette at the bottom of the image and then had a beer!
Original Base Images Used
This entry was posted on Monday, February 9th, 2015 at 6:42 pm
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